Contents

• Engine Swaps

• Where To Start

• A Louder Exhaust

• Finding What you want

• Upgrading

I've gotten a lot of email from people looking for upgrade suggestions, so I decided to add this page to simply suggest a course to go on.

Engine Swaps

Swapping engines may seem like a good way to improve performance, but it's usually not worth the effort. Unless you're changing your engine to one of the same type, for example replacing the stock 2.5L V-6 to a J-Spec 2.5L V-6, an engine swap (done right) will be extremely difficult. Upgrading from a four-cylinder to a V-6 will not only require that you get the engine, but the transaxle, accessories, and many engine related components as well. Even upgrading the first generation Probe's baseline 4-cylinder to a turbo will require drastic changes aside from simply installing the turbocharger. This includes pistons, intake manifold, exhaust manifold, ECU, all emission components, the instrument cluster, and much more. Cost-wise, engine swaps definitely aren't worth it. It would be much easier and cheaper to just buy a GT with the more powerful engine, since you'll also get the GT's perks as well... such as improved suspension and additional options.

Where To Start

I've gotten many letters asking where to start upgrading. If you're looking to be like everyone else and just add some extra power, go with headers, a muffler, and the usual plugs and wires. If you want true performance, it'll take a bit more time, thought, and of course, money. Start with replacing OEM parts. Making sure the engine is running in top condition will assure that you're starting off in good standings. If you're engine compression is low or your valves are leaking, your first few upgrades will be needed just to catch up to other stock Probes in better condition. Simple tasks, such as cleaning your intake system will cost you only a few dollars, but will allow your engine to breathe healthier.

A good area to start upgrading is standard OEM components. Performance plugs and ignition wires will make easy and quick improvements. Next is the intake system. Increasing the airflow into the engine will make vast improvements in power where the stock system was flawed. From there you'll need to decide what you want to do next and decide if any preparation is needed. Increasing the boost as a starting point or adding a turbo may cause a lean air/fuel ratio. Instead, prepare for it by upgrading the fuel pump, injectors, and maybe even adding a fuel management system. That should not only add power by themselves, but make more use of the power you add later.

Upgrading your exhaust system is also a good place to start, but it doesn't hurt to wait either. The size of your exhaust pipes should directly relate to how much power you want from your car. 2¼" pipes on a Probe with 200 horsepower will offer decent low range torque, but terrible high end power. On the other hand, 3" pipes on a 200 horsepower Probe will provide decent high end power with terrible low range torque. The key is to figure out how much horsepower you expect to have, then get a good size that matches. 2½" pipes on a 200 horsepower Probe would be most effective.

A Louder Exhaust

It seems that everyone wants a louder exhaust, but most people aren't interested in doing it the right way. Amateurs confuse the loud tone of a performance car with an exhaust and they go for the quick fixes. Oversized muffler tips and exhaust megaphones will amplify your exhaust sound, but do nothing for performance. These people may be fooling the other amateurs and idiots, but to everyone else they're a joke. I have yet to meet someone who's a true performance enthusiast and doesn't laugh at those ridiculous gadgets. They're nothing but childish gimmicks to make a louder exhaust. Any true performance enthusiast knows a true performance tone comes from the engine, not the rear of the exhaust. They can hear a fake exhaust from a mile away and nothing says 'Amateur' like that sound.

For the first year and a half since I bought my '91 GT, the exhaust system was almost completely stock, other then a hollowed out catalytic converter. This doesn't make it an overly quiet engine. Since a true performance tone will come from the engine, modifications to it will add power to compliment the increased sound. Increasing the air supply to the engine will produce a deeper, healthier engine tone. I've removed any resonators in the intake system, cleaned the manifold out completely, and added an air ram. That alone made an improvement in the tone. Additional upgrades, as well as a hollowed out catalytic converter gave my Probe a nominal tone at idle, but a louder, more powerful tone at mid to upper RPMs. It wasn't loud enough to wake up the neighborhood with a fake, tin can sounding exhaust, but its tone was unmistakably a result of a well catered engine.

What you need to realize it that overall, the Probe's engine, with exception of the V-6s, are relatively quite engines. Even if you remove the muffler completely, it really isn't as loud as one might expect. After I upgraded the exhaust on my '91 GT with a full turbo-back exhaust system, it still wasn't obnoxiously loud. It had a mildly deeper tone at idle, which was only tested to be a few decibels higher than then the previous exhaust, and had a deeper, solid mid and upper range tone, without thinning out. The key to this was not to oversize the pipes... if they get to big, aside from performance problems, they can end up echoing and sounding terrible.

Finding What You Want

The Probe does not have as much of an aftermarket following as the Mustangs and Eclipses, but there are plenty of options out there. The one thing you should never do is say 'they're not available for my car'. Off the shelf and direct bolt-ons may be limited when buying for a Probe, but if you have the time and resources, they certainly can become available. I've contacted places that specialize in BMWs and Volkswagens to find that they also have stuff for Probes that they don't even advertise. If you see a company offering something for other cars but not for the Probe, write or call and inquire about it. Many companies will look to help you get what you need even if they don't have it.

Upgrading

Here's a few lists to give you an idea of what to expect. Horsepower improvements are just an approximate number. Actual improvements will vary.

First Generation 2.2L 4-Cyl.

The non-turbo 2.2L engine starts out at only 110 horsepower and doesn't exactly have a huge aftermarket following, but considerable improvements are possible. Every upgrade you can find will do their own equal part in improving the power. The main things to focus on is the intake and exhaust, which can make modest improvements due to the restrictions on stock equipment. Finishing off with a custom computer upgrade will make use of the additional air, as well as allow the engine to run on premium fuel.

First Generation 3.0L V-6

The 3.0L V-6 is the hidden gem of the first generation Probes. These engines are capable of very high horsepower output, but need to be worked to get to their full potential. Although they have the least aftermarket following of all Probes, working with upgrades from a Ford Taurus will make drastic improvements. The main goal here is to increase the flow of the intake and exhaust, an then get control of the fuel system.

First Generation 2.2L Turbo

The 2.2L turbocharged engine is held back by a restrictive intake and a very conservative turbo setup. The turbo will boost to 7.3 psi and overboost to 9.3 during certain conditions at 3000 rpm. Increasing the boost as a starting point will make noticeable improvements, but will be overshadowed by the intake system and fuel system minimizing the effects. Starting out by opening up the intake will make an immediate improvement. When the intake is completely upgraded and unrestricted, as well as equal exhaust improvements, the fuel system can be tuned to achieve optimal power and well as adding the capability to tune the fuel as additional upgrades are added. This will maximize the impact of each additional performance upgrade as well as make the addition of a boost controller more rewarding.

Second Generation 2.0L 4-Cyl.

The 2.0L engine is very underpowered for an engine with so much potential. The key here is to add components from a J-Spec engine without using the engine block itself. This will keep the compression ratio down to a normal range, allowing the addition of a turbo sometime in the future, while adding the benefits of the J-Spec engine's improved intake system.

Second Generation 2.5L V-6

The 2.5L V-6 is the most popular engine of all the Probes when dealing with aftermarket manufacturers. You can add just about anything you want to improve its power. Adding the usual upgrades will allow the engine to creep toward 200 horsepower rather quickly. Adding some J-Spec components as well as upgrading the entire exhaust system will easily put the car in Mustang GT territory. Add a set of forged pistons and a cylinder overboring to 2.9L, this engine will produce an enormous amount of power without the need for nitrous oxide nor a turbocharger. Finishing it off with a turbocharger will make it almost unbeatable among the import competition.